Rescue ship for disabled vessels, vessels rescue method, and use of a rescue ship

ABSTRACT

A rescue ship for a disabled vessel includes a hull which delimits an elongated dock ( 12 ) which is at least 150 m long and preferably at least 250 m long and at least 30 m wide and preferably at least 45 m wide, and including a ballasting device enabling draught modification by at least 15 m and preferably at least 20 m. The hull has two lateral hulls capable of being ballasted ( 14 ) and enclosing the dock ( 12 ), and the stem has a practically sealed door ( 18 ) which can close the rear of the dock ( 12 ). The ship further includes maneuvering elements designed to exert a thrust in one direction transverse at least to the longitudinal axis of the ship. The invention is applicable to the rescue of disabled vessels.

This invention relates to a rescue vessel for vessels in distress, itsoperating process, and applications of such a vessel.

Damage of any type that occurs in tankers that transport toxic materialscreates pollution incidents called “oil slicks” in the case ofhydrocarbons. The consequences of these pollution incidents areconsiderable. It is possible to cite in particular the possible loss ofthe tanker by foundering (value of the vessel), the loss of a portion orall of the cargo, and primarily the considerable economic losses for thecoastal populations concerned (destruction of sites, destruction of fishfarms, destruction of wild animals, losses due to fishing, etc.).

These oil slicks are therefore the source of ecological problems thathave consequences on the political level.

It is further necessary to note that not only these pollution incidentscan be caused by accidents of tankers that are in poor condition or areold, but also that the same problems arise when the crew is incompetent,and in the case of much more recent tankers in good condition that werebuilt with high-resistance steels that allowed a reduction in thickness,a gain in weight and an increase of the tonnage. The tankers that areformed by these steels become worn out very quickly, however, and theypose the same problem as tankers that are dilapidated and in poorcondition.

To eliminate these problems, a first conceivable solution is the towingof the vessel to a location where it will do less damage in case itfounders. Experience has shown, however, that the situations thatproduce these pollution incidents generally occurred in very bad weatherand that it was virtually impossible to do this kind of towing duringthe first few days when the vessel is still afloat.

It was therefore conceivable to use pollution-cleanup vessels. Thesevessels are designed to vacuum up the hydrocarbons that are released byvessels in distress, in general after they have sunk. The largestpollution-cleanup vessels considered are able to remove only severalthousand tons of crude, and a large number of rotations between the siteof the disaster and a port that can accept the recovered materials aretherefore necessary in the case of a major oil slick. A considerableamount of time is therefore necessary and during the latter, the effectsof the oil slick can continue. These pollution-cleanup vessels aretherefore only a very partial solution. In addition, the latter can workonly in relatively calm weather and not during storms.

These pollution-cleanup vessels do not prevent the vessel in distressfrom sinking and from becoming at that time a sort of “delayed-actionbomb” that can create pollution incidents for long periods,independently of the significant ecological risk constituted by such avessel at the bottom of the sea.

If the causes of these pollution incidents or oil slicks are studied, itis noted that they are in general the fact of tankers that are subjectto damage (breaking of the hull, leaks, malfunctions) because of theirgreat age, or tankers that undergo maritime disasters (damages due tostorms, collisions or malfunctions) because of a crew's incompetence.

Aside from several rare cases where, following a collision, a vesselsinks very quickly, a very large majority of pollution incidents or oilslicks were caused by a vessel that continue to float for several days.In addition, a very large majority of the fleet of tankers have a totallength of less than 250 m and even 200 m.

The object of the invention is to eliminate the very large majority ofpollution incidents or oil slicks by very quickly rendering safe vesselsin distress that may be the cause of significant pollution incidents oroil slicks or similar dangers, such as chemical and biological risks.

The invention therefore has as its object the recovery both of thevessel and its cargo by its safeguarding in a way that then allowseither the repair or the recovery of the cargo, or these two operations.

For this purpose, the main object of the invention is the supplying of arescue vessel that has a basin of very large dimensions that can quicklyget up close to the vessel in distress and can place this vessel indistress into its basin whose dimensions are obviously quite larger thanthose of the vessel in distress.

According to document U.S. Pat. No. 5,215,024, a floating artificialisland that is equipped with basins that can be closed so that vesselscan be protected against heavy weather during their loading andunloading maneuvers is already known. The artificial island does nothave autonomous means of propulsion and cannot be ballasted, whereby itsfunction is to be as stationary as possible to perform its function. Itis not able to quickly get up close to a vessel in distress and to placethis vessel in distress in its basin.

According to document GB-2 144 680, a type of box that forms a floatingdock and that is designed to ensure, by ballasting and deballasting,surrounding a lateral hull of a floating platform to allow the repair ofthis hull is also known. The box has dimensions that are only slightlylarger than those of the lateral hull, and it does not have autonomouspropulsion means or even a form of vessel, because it is not intended tosail. It therefore does not constitute a rescue vessel that has a basinof very large dimensions that can quickly get up close to a vessel indistress and can place this vessel in distress within its basin.

According to document U.S. Pat. No. 5,988,093, a floating dock thatconstitutes a U-shaped structure that is intended to move along avessel, on the sides and under the bottom of the latter, for cleaningthe surface thereof, is also known. This dock is open on two ends, andit does not form a basin of very large dimensions.

According to document AU-482 040, a barge transport vessel whoseelongated hull delimits a space that is intended to contain barges thatare very close to one another and the sides of the vessel is also known.The internal space that is delimited by the hull does not constitute abasin because it is entirely open to the rear.

To reach its main object, which cannot be reached by any of the devicesof the above-mentioned documents, the invention relates to a rescuevessel for vessels whose hull delimits an elongated basin of at least150 m in length and 30 m in width and that comprises a ballast devicethat makes it possible to alter the vessel's draft by at least 15 m.

The basin preferably has a length of at least 250 m and a width of atleast 45 m, and the draft alteration can reach at least 20 m.

In a first embodiment, the hull comprises two lateral hulls that can beballasted and that surround the basin, and the stem has a virtuallysealed door that can close the rear of the basin.

In a variant, the door that can close the rear of the basin comprisestwo flaps that each comprise two parts that are articulated togetheraround a vertical axis that is intended to work with the vertical axisof the other flap when the door is closed. At least one of the ends ofthe two articulated parts that are distant from the vertical axis ispreferably attached to the corresponding vertical side of the rear hullby a slide that can move horizontally along the internal side of therear part of the hull.

In another variant, the door that is intended to close the rear of thebasin comprises a detachable panel that can be ballasted to move from afloor position that is close to the bottom of the basin to anapproximately vertical position of a door for closing the rear of thebasin.

In a first embodiment, it is advantageous that the vessel comprises atleast one winch for towing a vessel in distress that is entering thebasin by the stem.

In another embodiment, at least one side of the basin has a height thatis less by at least 15 m than that of at least two other sides. In anembodiment, the two longitudinal sides, port and starboard, bothpreferably have a height that is less by at least 20 m than that of theother two sides delimited to the front and to the rear of the vessel,and their upper edge is virtually rectilinear over the largest portionof its length. This edge is preferably provided with a reinforcement,advantageously having elasticity properties.

In all the embodiments, the rescue vessel preferably comprisesmaneuvering means that are intended to exert a thrust in a directionthat is transverse to at least the longitudinal axis of the vessel.

The rescue vessel preferably comprises guiding and holding devices of avessel inside the basin, such as hydraulic thrusters that areincorporated in the basin.

The rescue vessel preferably comprises stabilizers that stabilize it inthe presence of swells.

The rescue vessel preferably comprises moving, optionally articulatedpartitions that act as breakwaters against basin storms.

The invention also relates to a process for rescuing vessels in distresswith a rescue vessel that can be ballasted and that has a basin of theabove-mentioned type; the process comprises a first phase of movement ofthe rescue vessel toward the site of the vessel in distress; a secondphase, executed close to the vessel in distress, of ballasting therescue vessel such that at least one upper edge of the basin is foundbelow the level of the keel of the vessel in distress; a third phase ofintroducing the vessel in distress into the basin; and a fourth phase ofputting the upper edge of the basin above sea level.

The fourth phase of putting the upper edge at a level that is above sealevel is preferably carried out by closing a door of the basin.

The fourth phase of putting the upper edge of the basin above sea levelpreferably comprises the movement of the vessel in vertical direction byballasting, with evacuation of the water outside of the vessel.

Before the first phase or at the beginning of the latter, the processpreferably comprises the ballasting of the vessel with its smallestpractical draft.

The process also comprises, after the fourth phase, the movement of therescue vessel to a protected location that promotes the execution on thevessel in distress of an operation that is selected from among repairand unloading of the cargo.

The ballasting of the vessel with its smaller draft preferably comprisesthe evacuation of the basin.

The invention also relates to the application of a rescue vessel of theabove-mentioned type to the moving of marine farming modules at sea.

It also relates to the application of a rescue vessel of theabove-mentioned type in the formation of a dry dock.

It also relates to the application of a rescue vessel of theabove-mentioned type in the formation of an artificial port for smallboats in the case of a storm.

Other characteristics and advantages of the invention will better emergefrom the following description, done in reference to the accompanyingdrawing, in which:

FIG. 1 is a very schematic perspective view of a rescue vessel in afirst embodiment of the invention;

FIG. 2 is a very schematic perspective view of a rescue vessel in asecond embodiment of the invention;

FIG. 3 is a bird's eye view of a variant of the first embodiment;

FIG. 4 is a schematic sectional drawing of the variant of FIG. 3;

FIG. 5 is a bird's eye view of another variant of the first embodiment;and

FIG. 6 is a schematic sectional drawing of the variant of FIG. 5.

FIG. 1 shows a rescue vessel 10 that has a basin 12 of very largedimensions, delimited between two lateral hulls 14, a front part 16,rear doors 18 and a bottom 20. The vessel also has a bridge 22, shown inthe front, but that can occupy any other location on the vessel.

Although these elements were not shown, the vessel advantageouslycomprises propulsion engines, maneuvering engines that allow inparticular transverse movements to the front and to the rear,stabilizers, breakwaters, etc. It also comprises at least one winch thatmakes it possible to tow a vessel to make it enter into basin 12 whenrear doors 18 are open. This winch can be mounted on a gantry, eitherfixed, preferably above the door, or mobile along the basin. The vesselcan also comprise two gantries, one of which is mobile.

The rescue vessel also preferably comprises devices for guiding andholding a vessel in distress inside the basin, such as thrusters, forexample hydraulic thrusters, that are incorporated in the basin.

The use of the rescue vessel according to the embodiment of FIG. 1 isnow described.

When the alarm is given, rescue vessel 10, which is stationed in thecenter of its surveillance zone, with its empty basin 12, canimmediately be directed toward a vessel in distress at a high speed,because it has a low draft since its basin is empty and its hulls thatcan be ballasted can already be empty. Otherwise, they can be emptiedfrom the beginning of the movement so that the draft is as small aspossible in a manner compatible with the sea conditions and the currentnavigation possibilities.

When it approaches a vessel in distress, rescue vessel 10 can begin toflood the ballast tanks and to sink into the sea. At the same time,basin 12 starts to become filled, and doors 18 are opened wide. Thanksto its maneuverability, vessel 10, after having thrown a cable that isattached to the front or to the rear of the vessel in distress, or evenwithout a cable when the vessel in distress is again maneuvering, isoriented such that its rear part that is opened wide is rotated towardthe vessel in distress. The latter is then introduced into basin 12,either by its own means, or with the propulsion means of vessel 10 thatcan come close to the vessel in distress, either with the assistance ofa winch or with the assistance of any combination of these variousmeans. When the vessel has entered basin 12, doors 18 are closed.Compressed air, preferably previously held in compressed air tanks,expels water from the ballast tanks so that rescue vessel 10 risesrelative to sea level. From this time, any risk of pollution iseliminated. Actually, the vessel in distress is protected in the basinof the rescue vessel; even if it is in the state of sinking or breakingup, the possible pollution is limited to basin 12. Based on theparticular case of the vessel in distress, the basin can be emptied ornot, partly or completely. At this time, rescue vessel 10 can move tofacilitate operations such as the repair of the vessel or the unloadingof its cargo, for example by drawing closer to the side.

As the preceding description indicates, rescue vessel 10 can reach thelocation of the vessel in distress in a very short time, at most severalhours, and upon putting the vessel in distress in the basin, any risk ofpollution is eliminated. In addition, it makes it possible to preservethe vessel in distress that has not been lost and that most often can berecovered.

In an embodiment, the rescue vessel that is being considered has a basinof about 95 m in width and 400 m in length, whose rear doors have areach of at least about 48 m and a height of 78 m.

Maneuvering such doors by a single vertical articulation that is placedon one edge poses difficult technological problems. It is then useful toproduce such doors in triangulated form. More specifically, each flap ofthe double rear door can be in the form of two parts that arearticulated together around a vertical axis that is designed to workwith the vertical axis of the other flap in the closed position of thedoor. The ends of the two articulated parts that are distant from thevertical axis are themselves attached to the corresponding vertical sideof the rear hull. These attachments can be either simply articulated(for example at the rear end of the side of the vessel) or articulatedon a slide that can move horizontally along the side of the rear hull.The two attachments can also comprise slides.

In the case of the above-mentioned rescue vessel, the dimensions of thebasin are such that it can establish the known phenomenon under the nameof “basin storm.” It is then preferable to eliminate such storms thatcan constitute a serious impediment for handling the rescued vessel.Mobile partitions or breakwaters are then advantageously incorporatedbetween the two lateral hulls.

The above-mentioned triangulation system can also be applied to otherparts of the rescue vessel, for example to basin storm breakwaters, tothrusters for holding the rescued vessel, to handling gantry supportsplaced between the sides, etc.

In a variant embodiment of FIG. 1, the basin comprises a door such as 18at each end. It is then essential that the two lateral hulls beconnected by several fixed gantries. The various necessary elements arehoused in the two hulls.

In another variant embodiment of FIG. 1, at least one door, for examplea sliding door that has a height on the order of 40 m and a width on theorder of 25 to 30 m, can be formed at the front of the basin in alateral hull or at the front of the vessel. Such doors are intended toallow the exit of one or more tugs that could have been used for theintroduction of the rescued vessel into the basin. As this exit iscarried out when the basin is full, these doors are placed toward thetop of the lateral hulls. Two doors are preferably formed at the frontof each lateral hull so that the tugs can exit from the basin by thewindward side.

FIG. 2 shows another rescue vessel embodiment. More specifically, rescuevessel 24 of FIG. 2 comprises a hull 28 that delimits a basin 26, shownin parallelepipedic shape, although this shape, as in the firstembodiment, is not essential. In particular, the bottom is notnecessarily flat, and the basin may have, for example, a shape thatnarrows toward the bottom, in section via a transversal vertical plane.Such an arrangement can be adopted, for example, for the acceleration ofthe ballasting.

At each end, the vessel comprises a structure 30 that preferablycarries, at its upper part, a bridge. Structure 30 is not a simplesuperstructure. In fact, it is higher than FIG. 2 indicates such thatthe vessel can be almost completely immersed, whereby only the upperparts of structures 30 project above the sea. Of course, even in thisposition, the vessel has buoyancy reserves that make it unsinkable.

During the use of rescue vessel 24, the latter, which evacuated itsbasin 26, can be brought quickly to the location of the vessel indistress. When it approaches the vessel in distress, water is introducedinto the ballast tanks such that the rescue vessel sinks in the water.When it is beside the vessel in distress, upper edges 32 of the basinshould be under the water at a depth that is at least equal to the draftof the vessel in distress increased by a safety margin that depends onthe condition of the sea. Vessel 24, which has transversal propulsionmeans at its two ends, can be placed laterally under the vessel indistress, then compressed air is quickly introduced into its ballasttanks to expel the water. As soon as upper edges 32 of the basin areraised above the level of the lower part of the keel of the vessel indistress, the latter is trapped in the basin. The raising of rescuevessel 24 is carried out until the upper edges of the basin are abovesea level, at a desired height, taking into account the circumstancesand in particular the weather. At this time, as in the first embodiment,the vessel in distress can no longer create pollution.

Relative to the first embodiment, rescue vessel 24 of the secondembodiment offers the advantage of not requiring the maneuvering of anymoving part subject to the condition of the sea in any rescue operation.

Of course, the rescue vessels according to the invention have very largedimensions. So that they can avoid most of the pollution incidents oroil slicks, their basin 12 or 26 should have a length of at least 150 m,preferably at least 250 m, and very advantageously at least 300 m. Thewidth of the basin should be at least 30 m and preferably at least 50 mand even more. In the example that is indicated above, the rescue vesselthat is considered has a basin of about 95 m of width and 400 m oflength, and the height of the hull reaches 78 m. The rescue vessel thenhas considerable dimensions and mass, such that it is virtuallyunsusceptible to storms and can be used regardless of the condition ofthe sea. In addition, by its dimensions and mass, it makes it possible,by suitable positioning, to create a local calm that facilitates theentry into the basin of the vessel in distress, taking into account theswell and the current possibly present.

For the extremely improbable case where the rescue vessel would besubjected to a so-called “rogue” wave when it is responsible for avessel in distress, it may be advantageous to use redundant devices.Thus, the bridge, with its navigation systems, safety systems, etc., andthe engine room can each be duplicated. Thus, a machine room can beplaced in each of the lateral hulls. Of course, the parts that canundergo the most significant stresses can be suitably reinforced forthis purpose.

In the first embodiment, it is desirable that the ballasting of thevessel made possible a draft alteration on the order of 15 m andpreferably of at least 20 or 25 m. In the case of vessel 24 of thesecond embodiment, it is desirable that the draft variations can reach30 m and even more.

In reference to FIGS. 3 to 6, two variants of the first embodiment arenow described.

FIGS. 3 and 4 show, in a bird's eye view and in a longitudinal section,a rescue vessel 10 that has a basin 12 of about 95 m of width and 400 mof length, and the height of the hull reaches 78 m. A vessel in distress34 that is 150 m in length is shown in basin 12. It is realized in thesefigures that the introduction of the vessel in distress into the basin,either by its own means, or by means of propulsion and maneuvering ofthe rescue vessel, either with the assistance of a tug or by anycombination of these means, is easy, taking into account the very greatspace available for maneuvering.

FIGS. 5 and 6 show, in a bird's eye view and in longitudinal section, arescue vessel 10 that also has a basin 12 of about 95 m of width and 400m of length, and whose hull height reaches 78 mm. A vessel in distress38 that is 360 m in length is shown in basin 12. In this variant, therear part of the bottom of the basin consists of a detachable panel 40that constitutes a floor that can itself be ballasted. This floor,having, for example, a length of 80 m, can be reduced, as indicated inFIG. 6, to facilitate the entrance of a vessel in distress of very largedimensions.

In another variant, the rear part of the bottom comprises a floor and apanel, as indicated in 40, which can be ballasted and can slide bypivoting to close the rear, instead of doors 18 that are thensuperfluous. The maneuvering of this panel is then carried outessentially by ballasting.

Of course, the rescue vessel can comprise other equipment that issuitable for its missions, for example, a landing platform forhelicopters, means for anchoring vessels in distress, means for fightingfire of a vessel in distress before, during or after its entry into thebasin of the rescue vessel, means for treatment, in particular byfiltration, of water of the basin, means for storing waste, inparticular recovered by filtering or on the vessel in distress, and/ormeans for at least patching up a damaged vessel.

The rescue vessel according to the invention exhibits the followingconsiderable advantages.

First of all, it eliminates the problem of pollution as quickly aspossible, while preventing the vessel in distress from sinking and mostoften allowing its recovery. The cargo can also be recovered andoptionally pumped to a ground installation or to other vessels.

These possibilities for recovering the vessel and the cargo, on the onehand, and the elimination of all of the effects of pollution, on theother hand, represent considerable economic advantages.

Another considerable economic advantage is that it is no longernecessary to forbid the navigation of single-hull vessels in goodoperating condition, since the problems that they could pose can beeasily resolved. It is no longer necessary to establish ports of refugefor vessels in distress, whereby this solution, mentioned simply in atheoretical manner, offers such inconveniences that it is not probablethat it will ever actually be considered.

In addition, such vessels can be used not only to avoid such majorpollution incidents but also for other applications. In particular, theconstruction at sea of marine farms whose modules have large dimensions(on the order of one hundred meters and more) and that should sometimesbe moved has begun. Such a rescue vessel is perfectly suited for thispurpose.

The rescue vessel has other applications for transport of bulkystructures, such as vessels and parts of vessels, and drilling orproduction platforms and parts of such platforms.

The rescue vessel also makes possible the formation of a dry dock, forexample, in the case of moving a fleet.

Finally, in the case of a strong storm, such a rescue vessel can be usedas an artificial port to protect small boats.

If the rescue vessel is conventionally used only for the rescue ofvessels in distress, there are long periods during which it is onstandby, having enough room on the sides, taking into account its largedimensions and its draft. It can then be used as a support forenergy-generating devices of the renewable type. For example, it cancarry wind power engines or photovoltaic devices. The energy that isobtained can be either stored in electrical form or in chemical form,for example for being used by the vessel for its missions, ortransmitted to shore by a connecting device at sea.

Of course, various modifications can be provided by one skilled in theart to vessels, processes and applications that were just described onlyby way of non-limiting example without exceeding the scope of theinvention.

1-10. (canceled)
 11. Rescue vessel for vessels, of the type thatdelimits an elongated basin (12, 26) by at least 150 m in length and 30m in width, and that comprises a ballast device that makes it possibleto alter the vessel's draft by at least 15 m, characterized in that itcomprises a hull that comprises two lateral hulls that surround basin(12, 26) and that delimits at least one upper edge of basin (12, 26),and the ballast device operates between at least two positions in one ofwhich basin (12, 26) is evacuated and at least the upper edge is foundabove sea level, and in the other of which basin (12, 26) is fullbecause an end is found below the level of the keel of a vessel indistress.
 12. Rescue vessel according to claim 11, wherein basin (12,26) has a length of at least 250 m and a width of at least 45 m, and thedraft alteration can reach at least 20 m.
 13. Rescue vessel according toclaim 11, wherein the stern comprises a virtually sealed door (18) thatis intended to close the rear of basin (12) on the edge that is foundbelow the level of the keel of a vessel in distress.
 14. Rescue vesselaccording to claim 13, wherein the door that can close the rear of basin(12, 26) comprises two flaps that each comprise two parts that arearticulated together around a vertical axis that is designed to workwith the vertical axis of the other flap in a closed position of thedoor.
 15. Rescue vessel according to claim 13, wherein at least one ofthe ends of the two articulated parts that are distant from the verticalaxis is attached to the corresponding vertical side of the rear hull bya slide that can move horizontally along the internal side of the rearpart of the hull.
 16. Rescue vessel according to claim 13, wherein thedoor that can close the rear of basin (12) comprises a detachable panel(40) that can be ballasted to move from a position that is close to thebottom of the basin to an approximately vertical closing position of therear of basin (12).
 17. Rescue vessel according to claim 11, wherein thetwo port and starboard longitudinal sides (28) of the hull both have aheight that is lower by at least 20 m than that of the other twodelimited sides at the front and at the rear of the vessel, and theirupper edge (32) is virtually rectilinear on the largest part of itslength and is provided with a reinforcement.
 18. Rescue vessel accordingto claim 11, wherein it comprises maneuvering means that are intended toexert a thrust in a direction that is transverse to at least thelongitudinal axis of the vessel.
 19. Process for rescuing vessels indistress with the assistance of a rescue vessel (10, 24) that can beballasted and that has a basin (12, 26) according to claim 11, whereinit comprises a first phase of movement of rescue vessel (10, 24) towardthe location of the vessel in distress, a second phase, executed closeto the vessel in distress, of ballasting rescue vessel (10, 24) suchthat at least one upper edge of basin (12, 26) is found below the levelof the keel of the vessel in distress, and a third phase for introducingthe vessel in distress into basin (12, 26), and a fourth phase ofputting the upper edge of basin (12, 26) above sea level. 20.Application of a rescue vessel (10, 24) according to claim 11 withtransport of bulky structures that are selected from among the vesselsand parts of vessels, the drilling or production platforms, and theparts of such platforms, and the marine farming modules at sea.